Struct cell_gc::ptr::Pointer

pub struct Pointer<T> { /* fields omitted */ }

A pointer to some T in the GC heap.

Safety

A Pointer<T> is a small step up in safety from a raw pointer. A valid Pointer<T> instance is a guarantee that:

• The pointer points into the GC heap, within a GC-allocated page, and not on top of the PageHeader.

• The pointer has the alignment required by the type and GC.

Note that Pointer<T> does not pin its referent like GcRef<T> does. Therefore, a Pointer<T> can still easily be made to dangle or point at uninitialized memory! The Pointer<T> type is not for general use (use GcRef<T> for that instead), only for GC internals. We have to make it pub so that #[derive(IntoHeap)] can generate code that uses it, but no one else should!

Methods

impl<T> Pointer<T>

unsafe fn new(ptr: *const T) -> Pointer<T>

Construct a new Pointer<T> from a raw *const T.

Safety

It is the responsibility of callers to ensure that the guarantees mentioned above hold true.

Panics

Panics if the pointer is not aligned properly, or if it would clobber the GC's internal PageHeader.

fn is_null(&self) -> bool

Is this pointer null?

unsafe fn as_ref(&self) -> &T

Get a reference to the pointed-to T instance.

Safety

If a GC happens and reclaims the referent while the returned reference is in use, it will result in use-after-free.

If this pointer doesn't point at a valid T instance, then all hell will break loose.

Panics

Panics if the pointer is null.

fn as_raw(&self) -> *const T

Get the underlying raw pointer.

fn as_void(&self) -> *const ()

Get the underlying raw pointer as a *const ().

fn as_usize(&self) -> usize

Get the underlying raw pointer as a usize.

Trait Implementations

impl<T: Hash> Hash for Pointer<T>

fn hash<__HT: Hasher>(&self, __arg_0: &mut __HT)

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].

impl<T: PartialOrd> PartialOrd for Pointer<T>

fn partial_cmp(&self, __arg_0: &Pointer<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, __arg_0: &Pointer<T>) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, __arg_0: &Pointer<T>) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, __arg_0: &Pointer<T>) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, __arg_0: &Pointer<T>) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T: Ord> Ord for Pointer<T>

fn cmp(&self, __arg_0: &Pointer<T>) -> Ordering

This method returns an Ordering between self and other.

impl<T> Debug for Pointer<T>

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<T> Clone for Pointer<T>

fn clone(&self) -> Pointer<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Copy for Pointer<T>

impl<T> PartialEq for Pointer<T>

fn eq(&self, other: &Pointer<T>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<T> Eq for Pointer<T>